Sweeper assembly

ABSTRACT

This disclosure relates to a positive drive sweeper, such as a lawn sweeper, which permits elevation of the ground sweeping brush without disturbing the load in the hopper. The positive drive includes internal and external planetary bears within the wheel hub which drive the two brushes of the sweeper in opposite directions. The housing is pivotally mounted on the ground engaging wheel axis and the brushes are rotatably connected to the housing, whereby the ground sweeping brush may be raised for hauling by pivoting the housing about the wheel axis, without disturbing the load in the hopper.

United States Patent [1 1 Rhodes et al. 7

m1 3,823,435 [451 July 16,1974

[ SWEEPER ASSEMBLY [75] Inventors: Keith 11. Rhodes; William J.

Schlapman, both of Winnesconne,

Wis.

[73] Assignee: J. I. Case Company, Racine, Wis.

[22] Filed: Apr. 16, 1973 [21] Appl. No.: 351,396

[52] [1.8. CI. 15/79, 15/83 [51] Int. Cl E0lh 1/04 [58] Field of Search15/49 C, 79, 83,55

[56] References Cited UNITED STATES PATENTS 850,777 4/1907 Mosher 15/79UX- -2,448,328 8/1948 Russell 15/83 2,727,2641 12/1955 Dunham 15/795,591,883 7/1971 Armstrong et al 1S/79 Primary Examiner-Edward L.Roberts [5 7 ABSTRACT This disclosure relates to a positive drivesweeper, such as a lawn sweeper, which permits elevation of the groundsweeping brush without disturbing the load in the hopper. The positivedrive includes internal and external planetary bears within the wheelhub which drive the two brushes of the sweeper in opposite directions.The housing is pivotally mounted on the ground engaging wheel axis andthe brushes are rotatably connected to the housing, whereby the groundsweeping brush may be raised for hauling by pivoting the housing aboutthe wheel axis, without disturbing the load in the hopper.

16 Claims, 5 Drawing Figures 1 SWEEPER ASSEMBLY FIELD OF THE INVENTIONDESCRIPTION OF THE PRIOR ART The sweepers disclosed by the prior artgenerally include a ground sweeping brush which may be driven by therotation of the supporting wheels or the sweeper brush may be driven byan auxiliarypower source, such as a tractor or the like. A second brushor an impeller may be provided, adjacent and above the sweeper brush, topropel the leaves, grass or other debris from the sweeper brush into ahopper, normally located opposite the second brush. The second brush orimpeller is preferably rotated at a faster speed than the sweeper brushto prevent build-up of debris between the brushes and to propel thedebris intothe hopper. The second brush or impeller may also be drivenin the opposite direction to the sweeper brush. Examples of multiplestage sweepers include US. Pat. Nos. 517,709, 1,177,561, 1,332,429 and3,591,883, French Patent 501,386, published Apr. 13, 1920 andCanadian'Patent 454,l05,issued Jan. 18, I949.

, In the multiple stage lawn sweepers disclosed in the prior art, atleast one of the brushes or impellers are driven by a belt or chainwhich is subject to slippage and accidental removal. Another problemwith the small prior art lawn sweepers is that the. entire frame,including the hopper, must be raised to lift the sweeper brush fortransporting the sweeper assembly. The preferred embodiment of thesweeper assembly of this invention includes a positive drive for both ofthe brushes and the sweeper brush may be lifted or adjusted withoutdisturbing the'hopper load. Another important advantage of the disclosedsweeper brush is the simplicity of the positive drive assembly, which isdescribed more fully hereinbelow. i

SUMMARY or THE INVENTION I sides on the axis of the ground engagingwheels. A pair of rotary brushes are mounted within the housing to theopposed housing sides and the assembly includes a positive driverotating the brushes in opposite directions. The brushes include arotary ground engaging brush which collects leaves and other debris anda second rotary brush having an axis of rotation adjacent and above theground engaging brush. The second rotary brush transfers and propels thedebris collected by the ground engaging brush into a hopper.

In the preferred embodiment of the sweeper assembly, at least one of thewheels includes internal and external planetary gears concentric withthe axis of the wheels. The rotary brush shafts have pinion gearsmeshing with one of the planetary gears, drivingthe brushes in oppositedirections. The pinion gear of the ground engaging brush in thedisclosed embodiment meshes with the external rotary gear and the piniongear of the second rotary brush meshes with the internal planetary gear,such that the second rotary brush is driven at a greater speed than theground engaging brush to propel the debris lifted by the ground engagingbrush into the hopper and preventing backup of the debris within thehousing. In the disclosed embodiment, the wheel includes a hub having anannular channel concentric with the wheel axis. The planetary gears areprovided on the radially spaced opposed sides of the channel with theinternal planetary gear surrounding the external planetary gear. I

As described above, in the preferred embodiment of the sweeper assembly,the ground engaging brush may be raised from the ground, withoutdisturbing the hopper load. In the disclosed embodiment, the housing istiltably mounted on the axis of the wheels and the.

brushes are rotatably mounted on the housing, such that the groundengaging brush may be raised by tilting the housing about the wheelaxis. In the disclosed embodiment, the housing includes a releasablelock retaining the housing in a predetermined angular position, whichsets the position of the ground engaging brush. The housing positionlock is preferably adapted to retain the housing in a plurality ofpositions about the wheel axis, permitting adjustment of the position ofthe ground engaging brush, depending upon the application of the sweeperand raising of the ground engaging brush to transport the sweeperassembly; all without disturbing the load in the hopper. I The sweeperassembly housing normally includes internal bafiles which direct thedebris lifted by the ground engaging brush to the second rotary brushand directs the debris propelled by the second rotary brush into theenclosed hopper. In the disclosed embodiment, the housing includes anintegral baffle located between the second rotary brush and the hopperdefining an opening to the hopper between the top of the housing and thebaffle. Because the housing is adapted to be rotated or tilted on thewheel axis, the rearward baffle does not enclose the lower portion ofthe housing and must be separate from the hopper. In the preferredembodimenuthe hopper includes a flexible sealing flap,

which is continuous with the bottom wall of the hopper, to preventdebris from escaping from the hopper. The seal isnormally biased againsttherearward baffle, enclosing the housing chamber. The disclosedembodiment includes'a separate draw bar assembly including a fixed framemember connected to the wheel axes to pull or draw the sweeper assembly.The hopper is preferably rotatably connected to the fixed frame membersof the draw bar assembly, such that the load in the hopper is notdisturbed by movement of the housing, as described above, and the hoppermay be unloaded by rotating the hopper about the fixed frame members,preferably over the housing.

Other advantages and meritoreous features of the disclosed sweeperassembly will be more fully understood from the following description ofthe preferred embodiment, the drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end view of oneembodiment of the sweeper assembly of this invention;

FIG. 2 is a side view of the'sweeper assembly shown in FIG. 1;

FIG. 3 is a cross-sectional side'view of the sweeper assembly shown inFIG. 1, in the direction of view arrows 3-3; I

FIG. 4 is a top cross-sectional view of the direct drive for the sweeperassembly shown in FIG. 2, in the direction of view arrows 44; and

FIG. 5 is a partial side view of the sweeper assembly, similar to FIG.2, showing the raised position of the ground engaging brush.

DESCRIPTION OF THE PREFERRED EMBODIMENT The disclosed embodiment of thesweeper assembly includes an enclosed housing 22, ground traversing orengaging wheels 24, a hopper 26 and a draw bar assembly 28. As shown inFIG. 3, the assembly includes a rotary ground engaging'or sweeper brush32 and a second rotary brush 34 located adjacent and above the sweeperbrush 32 within the housing. As the sweeper assembly is drawn in thedirection of the arrow 30, the brushes are caused to rotate in oppositedirections, as shown by the arrows, to lift leaves, grass and otherdebris, which is propelled in to the hopper 26. The

sweeper brush 32 lifts the debris from the ground and the second rotarybrush 34 propels the debris into the hopper. The second rotary brush 34preferably rotates at a greater speed than the ground engaging brush 32,such that the debris picked up by the ground engaging brush does notaccumulate between the brushes and the material is propelled into thehopper, as described hereinbelow.

The ground engaging brush 32 includes a central shaft 36 which isparallel to the axis of the wheels 24. The second rotary brush 34includes a second shaft 38 which is parallel to the axis of the wheelsand above the plane of the sweeper brush 32, as shown in FIG. 3. Thehousing 22 also includes an upper baffle 40 which is secured to theupper wall 42 of the housing and is shaped to propel the debris'liftedby the sweeper brush 32 into the hopper. In the disclosed embodiment,the upper baffle includes a semi-circular portion surrounding thesweeper brush 32 and an arcuate porton partially surrounding the secondrotary brush and defining an opening between the baffle 40 and therearward baffle 44.

The rearward baffle 44 is preferably integral with the side wall 46 ofthe housing and includes an arcuate portion which conforms to the shapeof the second rotary brush. The baffles thus define a chamber whichgenerally conforms to the external shape of the brushes and serve todirect the debris into the hopper, as described above. In the disclosedembodiment, a reinforcing tie rod 48 is provided between the side walls46 to provide rigidity to the housing structure. A second function ofthe tie rod is to act as a recirculating lower baffle for the sweeperbrush 32 and a lower baffle for the interchange of debris from thesweeper brush 32 and the second rotary brush 34.

The preferred embodiment of the sweeper assembly includes a positivedrive for the brushes, as described above. The drive assembly is bestshown in FIG. 4. In the disclosed embodiment, the wheel 24 includes ahub 52 having a central portion 54 encircling the axis of the wheel. Thecentral portion 54 is rotatably mounted on a sleeve 56, which isinternally threaded for securement of the hub to the side wall 46 of thehousing. Bolts 58 and 60 retain the hub to the side wall 46 of thehousing and washers 62 and 64 may be provided, as shown, to providebearing support for the hub. In the disclosed embodiment, the hubincludes an annular channel 66, as shown in FIG. 4, which is concentricwith the axis of the wheel. The radial outer wall of the channelincludes an internal planetary gear 68 and the radial inner wall of thechannel includes an external planetary gear 70. The hub is retained onthe tire portion 74 of the wheel bya plurality of radial barbs 72.

In the disclosed embodiment, the shaft 36 of the sweeper brush 32includes a pinion gear 76, near the distal end of the shaft, which isreceived within the channel 66 and meshes with the external planetarygear to provide a positive drive for the sweeper brush 32. Similarly,the shaft 38 of the second rotary brush includes a pinion gear 78 whichis received within the annular channel 66 and meshes with the internalplanetary gear 68. The planetary gears therefore provide a positivedrive for both of the brushes. The pinion gears may be secured to thebrush shafts by any suitable means, such as the lock rings 80 shown inFIG. 4. In the disclosed embodiment, each of the shafts include abearing 82, such as a nylon bearing, which is received within a bearingsleeve 84 secured 'to the side wall of the housing, as by rivet 86. Inthe preferred embodiment, the pinion gears 76 and 78 are coupled totheir respectiveshafts through a conventional one-wayclutch, not shown,which permits the sweeper to be towed without dragging. The one-wayclutch may be I any conventional design which allows the unit, whentowed, to turn without locking or skidding of the wheels. I

The drive assembly shown in FIG. 4 thus provides a positive drive foreach of the rotary brushes of the sweeper assembly of this invention.The brushes are rotated in opposite directions because the sweeper brushis driven by the external planetary gear 70 and the second rotary brushis driven by the internal planetary gears 68. Further, the second rotarybrush 34 is driven at a slightly greater speed than the sweeper brush 32because the outer wall of the channel 66, including the internalplanetary gear, rotates in teeth per second at a slightly greater speedthan the external planetary gear 70. It will also be noted that thebrushes are rotatably supported on the housing, such that the positionof the brushes may be adjusted by rotating or pivoting the housing aboutthe wheel axis, as described hereinbelow.

The draw bar assembly 28, as shown in FIG. 2, includes a pair of drawbars 90, which may be connected to a tractor or other vehicle to pullthe sweeper assembly along the ground, as shown by the arrows 30 inFIGS. 2 and 3. In the disclosed embodiment, an angle 92 is secured toeach of the draw bars for securement of the draw bar to the wheels 24. Astationary frame 94 is secured to each of the angles, as shown in FIG.2, by a screw 96 or other suitable means. The draw bar is secured to theangles, in the disclosed embodiment, by threaded fasteners 98. Thestationary frame members 94 are each secured to the wheels by bolts 60,as shown in FIG. 4, and spacer 95 is provided between the stationaryframe members and the side walls 46 of the housing, as shown.

In the disclosed embodiment, the frame 94 includes an elongated slot 91,as shown in FIGS. 2 and 3, which receives the'shaft 38 and bearing 82,as shown in FIG. 4. The frame 94 is preferably thinner than the spacer95 to permit relative movement of the frame and side wall 46, asdescribed below and shown in FIGS. A wheel debris cover 93 may also beprovided to protect the gears, as shown. In the assembly, the bearingsleeve 56 is tightly clamped to the cover 93, which is in turn clampedto the spacer 95 and side wall 46 of the housing by bolt 60. A losethrust washer 67 is provided between the bearing sleeve 56 and thedebris cover 93 to reduce frictional wear between the elements.

The hopper 26 may be of any conventional type. In the disclosedembodiment, the hopper 26 includes upper tubular frame members 102, asshown in FIG. 2, lower tubular frame members 104 and a fabric covering112, such as canvass. The ends 106 and 108, respectively, of the upperframe 102 and the lower frame 104 are flattened, as shown in FIG. 2, androtatably secured to the stationary frame members by bolts 110. Inoperation, the hopper may then be rotated from the position shown inFIG. 2, over the housing 22, to empty the hopper, as is known in thepriorart.

As described above, the housing 22 may be rotated or pivoted about thewheel axis def ned by the bearing sleeve 56 to adjust the position ofthe sweeper brush and particularly to raise the sweeper brush 32 totransport the sweeper assembly to a disposal area for the debriscollected in the hopper 26. Itis particularly important that the hopperload is not disturbed during adjustment of the sweeper brush, asrequired in the prior art,

andthat the hopper load does not have to be raised for transportation.The upper wall 42 of the housing in the disclosed embodiment includes avertical flange 114 parallel to the stationary frame 94, as shown inFIGS.

1, 2 and 3. The stationary frame includes a plurality of apertures 116with the centers of the apertures 116 defined on an arc generated fromthe axis of the wheels, as shown in FIG.2. The housing flange 114includes a locking or latching means 118 to secure the housing to thestationary frame in a plurality of positions, as described below. In thedisclosed embodiment, the latching means includes a boss 120 on thehousing flange, as shown in FIG. 1, a lock pin 122, best shown in FIG.3, and a spring 124 retaining the pin in the boss 120 and biasing thepin into the locking position.

The position of the housing and brushes is adjusted by releasing thelock pin 122, manually pivoting or rotating the housing about the wheelaxis and releasing the pin, which islockingly received within one of theapertures 116. For example, the sweeper brush 32 has been raised inxthesweeper assembly shown in FIG. 5 by releasing the locking pin, normallyin the position shown in FIG. 2, rotating the housing in the directionof the arrow and securing the latching'means as shown in FIG. 5. Thesweeper assembly may then be transported, without sweeping, because thesweeper brush 32 has been raised from the sweeper position. Further, andmost important, the position of the sweeper brush has been adjustedwithout disturbing the load in the hopper 26 because the housing is notconnected to the hopper. In the disclosed embodiment, a flexible sealingflap 130 is secured to the lower frame 104 of the hop per, which isbiased against the rearward baffle 44, as shown in FIG. 3. The sealingflap 130 prevents escape of debris collected within the hopper bysealing the space between the bottom wall and the baffle 44. The sealingflap may be formed of any suitable material, including a syntheticrubber or a plastic material, which is preferably flexible.

It is understood that certain modifications may be made to the sweeperassembly disclosed in the drawings without modifying the importantfeatures of this invention. For example, a latching means, such as shownat 118 in FIG. 1, maybe provided at both sides Y of the housing tosecurely retain the position of the housing. The positive drive for thebrushes, best illustrated in FIG. 4, may be provided in one wheel orbothwheels, depending upon the size and application of the sweeper. Thematerials of the sweeper assembly are generally known in the art. Thebrushes 32 and 34 may be natural or synthetic filament and variousmetals, including steel, may be utilized for the housing, frame, drawbar and wheel hubs. I r

In operation, the sweeper assembly is normally drawn along the area tobe swept, as indicated by. the arrow 30 in FIG. 3. The draw bar 90 maybe connected to a lawn power mower or tractor or any other suitablevehicle. The rotation of the wheels rotates the brushes in oppositedirections to lift the grass, leaves or other de bris' to be collectedand propels the debris into the hop per 26. The planetary gears 68 andprovide a positive drive for both of the brushes 32 and 34 and thesecond rotary brush 34 is driven at a slightly greater speed to propelthe debris collected by the sweeper brush 32 into the hopper.

The position of the sweeper brush 32 is adjusted by releasing the latchmeans 118 and rotating the hopper to the desired position for the brush32 and locking the latch means. The hopper load is not disturbed inthisadjustment because the housing is not secured to the hopper.

We claim:

1. A sweeper assembly, comprising: ground traversing wheels, at leastone of said wheels having internal and external planetary gearsconcentric with the axis of i said wheels, a rotary ground engagingbrushhaving an axis of rotation parallel to the axis of said wheels andhaving a pinion gear meshing with one of said planetary gears, a secondrotary brush having an axis of rotation parallel to the axis of saidwheels, above the plane of said ground engaging brush and having apinion gear meshing with the other of said planetary gears, saidplanetary gears providing said brushes with a positive drive in oppositedirections, and a housing enclosing said brushes and directing thedebris collected by said brushes to a collection means.

2. The sweeper assembly defined in claim 1, characterized in that saidhousing is tiltably mounted on the axis of said wheels and said brushesare rotatably. mounted on said housing, such that said ground engagingbrush may be raised by tilting said housing about said wheel axis.

3. The sweeper assembly defined in claim 2, characterized in that saidhousing includes a releasable locking means retaining said housing in apredetermined position and setting the position of said ground engagingbrush, said locking means adapted to retain said housing in a pluralityof positions about said wheel axis to set said brushes in apredetermined position.

4 The sweeper assembly defined in claim 1, characterized in that saidhousing includes a baffle located between said second rotary brush. andsaid collection means defining an opening above said second rotary brushand said sweeper assembly including a flexible seal normally biasedagainst said baffle and continuous with the bottom wall of saidcollection means, retaining debris within said collection means.

5. The sweeper assembly defined in claim 4, characterized in that saidcollection means is an enclosed hopper and said sweeper assemblyincludes a draw bar and stationary frame assembly connected to said drawbar, said hopper pivotally connected to said frame assembly to permitremoval of the debris collected within said hopper by pivoting saidhopper about said frame assembly.

6. A sweeper assembly, comprising, in combination, a pair of groundengaging wheels, at least one of said wheels having a hub, said hubhaving internal and external planetary gears concentric with the axis ofsaid wheel, a rotary ground engaging brush on a shaft parallel to saidwheel axis, said shaft having a gear meshing with said externalplanetary gear, a secondary rotary brush on a second shaft parallel tosaid wheel axis and above the axis of said ground engaging brush, saidbrushes in close proximity, said second brush shaft having a gearmeshing with said intemal planetary gear, said planetary gearspositively driving said brushes in opposite directions upon rotation ofsaid wheel, whereby debris sweep by said ground engaging brush istransferred by said second rotary brush to a hopper, and a housingenclosing said brushes.

7. The sweeper assembly defined in claim 6, characterized in that saidhub includes an annular channel concentric with said wheel axisreceiving said brush gears, said planetary gears defined on opposedradially spaced faces of said channel.

8. The sweeper assembly defined in claim 7, characterized in that saidinternal planetary gear surrounds said external planetary gear, suchthat said second brush is rotated at a greater speed than said groundengaging brush.

9. The sweeper assembly defined in claim 6, characterized in that saidhousing is pivotally mounted about an axis concentric with the axis ofsaid wheels and said axels are rotatably connected at opposite ends tosaid housing, whereby said ground engaging brush may be raised bypivoting said housing about said wheel axis.

sides to the axis of a pair of ground engaging wheels, a

ground engaging brush within said housing rotatably bris from saidhopper.

connected to said opposed housing sides, a second brush within saidhousing rotatably connected to said opposed housing sides, having anaxis of rotation adjacent and above said ground engaging brush, apositive drive means rotating said brushes in opposite directions,whereby debris collected by said ground engaging brush is transferredand propelled by said second rotary brush to a hopper, and an adjustablestop means retaining said hopper in selected predetermined positionsabout said wheel axis, retaining said brushes in selected positions andpermitting raising of said ground engaging brush for transfer of saidsweeper assembly.

'12. The sweeper assembly defined in claim 11, characterized in thatsaid sweeper assembly includes a draw bar assembly connected to saidwheel axis and said hopper is pivotally connected to said draw barassembly, whereby said housing may be pivoted about said wheel axis toraise said ground engaging brush without changing the position of saidhopper.

13. The sweeper assembly defined in claim 11, characterized in that saidpositive drive assembly comprises internal and external planetary gearsconcentric with said wheel axis and said brushes each including a piniongear meshing with one of said planetary gears, rotating said brushes inopposite directions.

14. The sweeper assembly defined in claim 13, characterized in that atleast one of said wheels includes a hub assembly having said planetarygears, said internal planetary gear surrounding said external planetaryear.

g 15. The sweeper assembly defined in claim 14, characterized in thatthe pinion gear of said ground engaging brush meshes with said externalplanetary gear and the pinion gear of said second rotary brush mesheswith said internal planetary gear, whereby said second brush is rotatedat a greater speed than said ground engaging brush.

16. The sweeper assembly defined in claim 11, characterized in that saidhousing includes integral baffle means directing the debris propelled bysaid brushes to said hopper and defining an opening in said housing tosaid hopper and a flexible sealing flap continuous with the bottom wallof said hopper and normally biased against said baffle means preventingthe escape of de-

1. A sweeper assembly, comprising: ground traversing wheels, at leastone of said wheels having internal and external planetary gearsconcentric with the axis of said wheels, a rotary ground engaging brushhaving an axis of rotation parallel to the axis of said wheels andhaving a pinion gear meshing with one of said planetary gears, a secondrotary brush having an axis of rotation parallel to the axis of saidwheels, above the plane of said ground engaging brush and Having apinion gear meshing with the other of said planetary gears, saidplanetary gears providing said brushes with a positive drive in oppositedirections, and a housing enclosing said brushes and directing thedebris collected by said brushes to a collection means.
 2. The sweeperassembly defined in claim 1, characterized in that said housing istiltably mounted on the axis of said wheels and said brushes arerotatably mounted on said housing, such that said ground engaging brushmay be raised by tilting said housing about said wheel axis.
 3. Thesweeper assembly defined in claim 2, characterized in that said housingincludes a releasable locking means retaining said housing in apredetermined position and setting the position of said ground engagingbrush, said locking means adapted to retain said housing in a pluralityof positions about said wheel axis to set said brushes in apredetermined position.
 4. The sweeper assembly defined in claim 1,characterized in that said housing includes a baffle located betweensaid second rotary brush and said collection means defining an openingabove said second rotary brush and said sweeper assembly including aflexible seal normally biased against said baffle and continuous withthe bottom wall of said collection means, retaining debris within saidcollection means.
 5. The sweeper assembly defined in claim 4,characterized in that said collection means is an enclosed hopper andsaid sweeper assembly includes a draw bar and stationary frame assemblyconnected to said draw bar, said hopper pivotally connected to saidframe assembly to permit removal of the debris collected within saidhopper by pivoting said hopper about said frame assembly.
 6. A sweeperassembly, comprising, in combination, a pair of ground engaging wheels,at least one of said wheels having a hub, said hub having internal andexternal planetary gears concentric with the axis of said wheel, arotary ground engaging brush on a shaft parallel to said wheel axis,said shaft having a gear meshing with said external planetary gear, asecondary rotary brush on a second shaft parallel to said wheel axis andabove the axis of said ground engaging brush, said brushes in closeproximity, said second brush shaft having a gear meshing with saidinternal planetary gear, said planetary gears positively driving saidbrushes in opposite directions upon rotation of said wheel, wherebydebris sweep by said ground engaging brush is transferred by said secondrotary brush to a hopper, and a housing enclosing said brushes.
 7. Thesweeper assembly defined in claim 6, characterized in that said hubincludes an annular channel concentric with said wheel axis receivingsaid brush gears, said planetary gears defined on opposed radiallyspaced faces of said channel.
 8. The sweeper assembly defined in claim7, characterized in that said internal planetary gear surrounds saidexternal planetary gear, such that said second brush is rotated at agreater speed than said ground engaging brush.
 9. The sweeper assemblydefined in claim 6, characterized in that said housing is pivotallymounted about an axis concentric with the axis of said wheels and saidaxels are rotatably connected at opposite ends to said housing, wherebysaid ground engaging brush may be raised by pivoting said housing aboutsaid wheel axis.
 10. The sweeper assembly defined in claim 9,characterized in that said housing includes a releasable stop meansretaining said housing in a predetermined position about said wheelaxis.
 11. A sweeper assembly, comprising: an enclosed, downwardlyopening housing having a top wall and side walls, said housing pivotallyconnected at opposed sides to the axis of a pair of ground engagingwheels, a ground engaging brush within said housing rotatably connectedto said opposed housing sides, a second brush within said housingrotatably connected to said opposed housing sides, having an axis ofrotation adjacent and above said ground engaging brush, a positive drivemeans rOtating said brushes in opposite directions, whereby debriscollected by said ground engaging brush is transferred and propelled bysaid second rotary brush to a hopper, and an adjustable stop meansretaining said hopper in selected predetermined positions about saidwheel axis, retaining said brushes in selected positions and permittingraising of said ground engaging brush for transfer of said sweeperassembly.
 12. The sweeper assembly defined in claim 11, characterized inthat said sweeper assembly includes a draw bar assembly connected tosaid wheel axis and said hopper is pivotally connected to said draw barassembly, whereby said housing may be pivoted about said wheel axis toraise said ground engaging brush without changing the position of saidhopper.
 13. The sweeper assembly defined in claim 11, characterized inthat said positive drive assembly comprises internal and externalplanetary gears concentric with said wheel axis and said brushes eachincluding a pinion gear meshing with one of said planetary gears,rotating said brushes in opposite directions.
 14. The sweeper assemblydefined in claim 13, characterized in that at least one of said wheelsincludes a hub assembly having said planetary gears, said internalplanetary gear surrounding said external planetary gear.
 15. The sweeperassembly defined in claim 14, characterized in that the pinion gear ofsaid ground engaging brush meshes with said external planetary gear andthe pinion gear of said second rotary brush meshes with said internalplanetary gear, whereby said second brush is rotated at a greater speedthan said ground engaging brush.
 16. The sweeper assembly defined inclaim 11, characterized in that said housing includes integral bafflemeans directing the debris propelled by said brushes to said hopper anddefining an opening in said housing to said hopper and a flexiblesealing flap continuous with the bottom wall of said hopper and normallybiased against said baffle means preventing the escape of debris fromsaid hopper.